paprika3d (the three.js toolset for coding agents) MCP server

paprika3D: the toolset that makes your coding agent a better three.js developer

paprika3D is a Claude Code plugin and MCP server that lets a coding agent open, look at, play, measure and fix the three.js, React Three Fiber and WebGL pages it writes, before it tells you they are done: it sees the scene as data, plays the page on an exact clock, inspects any mesh or value, builds shapes with real geometry, and speeds up the frame.

Install

Needs Google Chrome and Node 20.11 or later.

claude plugin marketplace add paprika3d/paprika3d
claude plugin install paprika3d@paprika3d

Chrome is found at its usual macOS path; elsewhere, set PAPRIKA3D_CHROME to the Chrome executable. For other agents, see Other agents.

Docs: https://paprika3d.com/docs. The window.__game convention: https://paprika3d.com/docs/convention. For LLMs: https://paprika3d.com/docs/llms.txt.

It works on any three.js, React Three Fiber or WebGL page: a game, a product viewer or configurator, a simulation, a shader or post-processing demo. The page needs no changes to be opened, looked at, driven and inspected.

What your agent gets

A three.js page is one : from outside it is a picture. paprika3D works inside it, with the 3D scene itself.

It never captures your screen: every picture is of its own headless page.

What it catches

Here is game_look on a mini golf page an agent wrote from a spec that said "scale the car to 0.8":

On screen (14):
Mesh 17.4% [399, 240, 880, 771]
…
Never visible: ToyCar (0.0338 units, in view), Glass (0.0168 units, in view)

The car is there, in view, and 3 cm long on an 8-metre course. In the runs below, two agents opened a page like this, looked at the screenshot and still missed the car; this line names it.

Measured with Sonnet 5.5 in clean installs, on long, exact three.js specs that each ship a glTF model:

Shortened. The full README is on GitHub.